Laundry appliance

ABSTRACT

A laundry appliance comprises a drum for receiving articles to be laundered, the drum comprising at least two rotatable drum portions and a drive capable of operating the drum in a plurality of different drum modes. The drum modes include a mode in which the rotatable drum portions are driven so as to cause relative rotation between them. A controller ( 100 ) controls the appliance to perform a plurality of different wash programmes, each wash programme having an associated drum mode. Each wash programme comprises a sequence of stages, with a drum mode being associated with each stage. The drum modes can differ in respect of (a) use (or non-use) of relative rotation between the drum portions (b) the ratio of time that the drum portions rotate compared to the time that they are at rest, and (c) the speed at which the drum portions are rotated. The intensity of a wash programme can be varied, inter alia, by varying the length of the wash stage.

[0001] The present invention relates to a laundry appliance such as awashing machine or washer-dryer and to a control apparatus for such amachine.

[0002] Conventional washing machines operate by agitating textilearticles within a rotating drum in the presence of water and detergentso that dirt is released from the fibres of the textile articles intothe water. The agitation is caused, in the case of front-loading washingmachines, by the rotation of the drum about a generally horizontal axisso that the textile articles tumble over one another and rub againsteach other and against the walls of the drum. However, the rotationalspeed of the drum is limited because, if the speed is too high, thetextile articles will merely be pressed under centrifugal forces againstthe interior walls of the drum. The articles then rotate with the drumand no agitation with respect to the drum or with respect to otherarticles is achieved. The amount of agitation which can be applied tothe textile articles by front-loading washing machines is thereforelimited. This means that, in order to achieve a specific standard ofcleanliness, the machine must operate for a minimum period of time.

[0003] International Patent Application WO99/58753 describes a washingmachine in which the drum comprises two rotatable drum portions whichare driven in such a way that relative rotation is produced between thedrum portions. The relative rotation between the drum portions gives amore vigorous agitation of the articles within the drum, treating themmore intensively than they would be in conventional apparatus andconsequently dirt is released from the textile articles at a higher ratethan in other machines.

[0004] The present invention seeks to provide an improved laundryapparatus.

[0005] Accordingly, a first aspect of the invention provides a laundryappliance comprising a drum for receiving articles to be laundered, thedrum comprising at least two rotatable drum portions and a drive capableof operating the drum in a plurality of different drum modes, includinga drum mode in which the rotatable drum portions are driven so as tocause relative rotation between the adjacent rotatable drum portions,and a controller which is capable of controlling the appliance toperform a plurality of different wash programmes, each wash programmehaving an associated drum mode.

[0006] This has the advantage that each wash programme uses a drum modewhich is appropriate for the type of load that is to be washed duringthat wash programme.

[0007] Preferably, in one of the wash programmes, the controllercontrols the drive to operate in a drum mode in which the drum portionsare not rotated relative to one another at any point during the washprogramme. This has the advantage that the drum can accommodate a loadof the type which would not normally be suited to this type ofappliance, such as a duvet.

[0008] The portions of the drum can be rotated in opposite directions atthe same or different speeds. Alternatively, each of the portions of thedrum can be rotated at a different speed in the same direction.

[0009] Preferably the appliance has a control panel for allowing a userto select an intensity for the chosen wash programme, such as whenclothes are more heavily or more lightly soiled than normal. Thecontroller is arranged to vary, in use, the intensity of the washprogramme in accordance with the selection made by a user. The intensityof the wash programme can be varied by varying the length of the washportion of the wash programme, varying the ratio of time during whichthe drum portions are rotated relative to one another compared to thetime during which the drum portions are not rotated or varying the speedof relative rotation between the drum portions. The latter two optionshave the advantage of allowing the wash intensity to be varied withoutincreasing the length of the wash programme.

[0010] A further aspect of the invention provides a control apparatusfor the laundry appliance.

[0011] Embodiments of the invention will now be described with referenceto the accompanying drawings, in which:

[0012]FIG. 1 is a cross-sectional view of a washing machine embodyingthe present invention;

[0013]FIG. 2 shows a control system for the machine of FIG. 1;

[0014]FIG. 3 shows one form of control panel for the, machine of FIG. 1;

[0015] FIGS. 4A-4C show one drum mode performed by the machine of FIG.1;

[0016] FIGS. 5A-5C show another drum mode performed by the machine ofFIG. 1;

[0017]FIGS. 6 and 7 are tables which give details of the wash programmesperformed by the machine of FIG. 1 and FIG. 8 is a key for these tables.

[0018]FIG. 1 shows a washing machine 10 which includes an outer casing12 in which a stationary tub 40 is located. A drum 50 is mounted insidethe tub 40 so as to be rotatable about an axis 85. The tub 40 iswatertight except for an inlet 21 and outlet 22. The washing machine 10includes a soap tray 20 capable of receiving detergent in a knownmanner. At least one water inlet 23 communicates with the soap tray 20and is provided with suitable means for connection to a water supplywithin the environment in which the washing machine 10 is to be used. Aconduit 21 is provided between the soap tray 20 and the tub 40 so as toallow water introduced via the inlet 23 to enter the tub 40. The tub 40has a sump 26 located beneath the drum 50. A drainage pipe 28communicates with the sump 26 and leads to a water outlet 30 via whichwater can be discharged from the washing machine 10. A pump 42 isprovided to allow water to be pumped from the sump 26 to the wateroutlet 30 at appropriate stages of the washing cycle carried out by thewashing machine 10.

[0019] The drum 50 is rotatably mounted about the axis 85 by way of ashaft 80. The shaft 80 is mounted in a known manner, allowing the tub 40to remain stationary whilst the drum 50 is rotatable with the shaft 80.The shaft 80 is rotatably driven by a motor (not shown) mounted withinthe outer casing 12 of the washing machine 10. A door 66 is located inthe front panel 12 a of the outer casing 12 to allow access to theinterior of the drum 50. It is via the door 66 that a wash load can bedeposited within the drum 50 before a wash cycle commences and removedfrom the drum 50 at the end of the wash cycle.

[0020] Drum 50 comprises two portions 60, 70 which are mounted such thatthey can be rotated with respect to one another. A drum of this type isdescribed more fully in International Patent Application WO99/58753.Typically the drum portions 60, 70 are rotated in opposite directions toone another, i.e. one portion clockwise, one counter-clockwise, but theycan also be rotated together in the same direction. The drum 50 ismounted in a cantilever fashion on the wall of the tub 40 remote fromthe door 66. The first outer rotatable portion 60, is supported on ahollow cylindrical shaft 81. An angular contact bearing 82 is locatedbetween the rear wall of the tub 40 and the hollow cylindrical shaft 81.The outer rotatable portion 60 is dimensioned so as to substantiallyfill the interior of the tub 40. More specifically, the outer rotatableportion 60 has a generally circular rear wall 63 extending from thehollow cylindrical shaft 81 towards the cylindrical wall of the tub 40,a generally cylindrical wall 61 extending generally parallel to thecylindrical walls of the tub 40 from the rear wall 63 towards the frontwall of the tub 40, and a generally annular front face 64 extending fromthe cylindrical wall 61 towards the door 66. Sufficient clearance isallowed between the walls 61, 63, 64 of the outer rotatable portion 60and the tub 40 to prevent the outer rotatable portion 60 from cominginto contact with the tub 40 when the drum 50 is made to spin.

[0021] An inner cylindrical wall 62 is also provided on the interior ofthe cylindrical wall 61 of the outer rotatable portion 60. The innercylindrical wall 62 extends from a point which is substantially midwaybetween the rear wall 63 and the front face 64 to the front face 565.The space between the interior cylindrical wall 62 and the cylindricalwall 61 is hollow but, if desired, could be filled with a strengtheningmaterial. In this event, the strengthening material must be lightweight.The provision of parallel cylindrical walls 61, 62 in the portion of theouter rotatable portion 60 closest to the front face 64 providesstrength to the whole of the outer rotatable portion 60 whilst reducingthe internal diameter of the outer rotatable portion 60 in this region.

[0022] The inner rotatable portion 70 is supported on a central shaft80, which in turn, is supported by deep groove bearings 83 locatedbetween the central shaft 80 and the hollow cylindrical shaft 81. Theinner rotatable portion 70 essentially comprises a generally circularrear wall 71 extending from the central shaft 80 towards the cylindricalwall of the tub 40, and a cylindrical wall 74 extending from theperiphery of the rear wall 71 towards the front wall of the tub 40. Thediameter of the cylindrical wall 74 of the inner rotatable portion 70 issubstantially the same as the diameter of the inner cylindrical wall 62of the outer rotatable portion 60. The cylindrical wall 74 of the innerrotatable portion 70 is dimensioned so that its distal end approachesthe end of the cylindrical wall 62 closest to it. It is advantageous tokeep the gap between these two cylindrical walls 62, 74 as small aspossible. An annular sealing ring 76 is located on the cylindrical wall61 of the outer cylindrical portion 60 immediately adjacent to the endof the inner cylindrical wall 62 closest to the inner cylindricalportion 70 so as to provide support for the distal end of thecylindrical wall 76 thereof.

[0023]FIG. 2 shows part of the control system of the machine 10. Acontroller 100 operates according to a control program stored on anon-volatile memory 105. The controller 100 is preferably implemented inthe form of a microcontroller but other ways of implementing thecontroller, such as an implementation entirely in hardware, will beapparent to the reader and are intended to fall within the scope of thisinvention.

[0024] An interface 110 interfaces the controller 100 to other parts ofthe machine 10. Sensors placed on the machine return signals to theinterface 110. The sensors include a water temperature sensor formonitoring temperature of the wash water in the sump of the machine 10and a motor speed sensor. The interface 110 also outputs signals tocontrol operation of the display 220 to display text messages andsignals to control the illumination of indicator lamps 215, 265 on thecontrol panel 120. Interface 110 also receives inputs from each of thecontrol buttons 210, 230, 240, 250, 260 on the control panel 120 whichallows the controller 100 to determine what button a user has pressed.The interface 110 also outputs a set of control signals 140 to controlthe operating state of various parts of the machine, such as the doorlock, water inlet valves, and the motor M. In a well-known manner, thecontrol software 105 controls operation of the machine according to theinputs it receives and issues outputs 140 for controlling various partsof the machine.

[0025] The speed of motor M is controlled on the basis of the monitoredsupply voltage and motor speed inputs to the interface and an outputsignal 145 to motor drive 130. Control signal 145 controls the firingangle of the triac (or other power switching device) in the motor drivecircuit 130. Another output signal 144 controls the direction ofrotation of the motor M and a further output signal 146 controls thestate of the gearbox. The state of the gearbox determines whether thedrum portions 60, 70 are rotated in unison or whether they are rotatedrelative to one another. Motor M can be used to drive both drum portions60, 70 or two separate motors may be provided, one motor being used todrive each of the drum portions 60, 70.

[0026]FIG. 3 shows one embodiment of control panel 120 in more detail.It will be appreciated that the control panel can vary from the oneshown here. For example, the control panel 120 may provide a differentrange of options, the type of control may vary e.g. push button,touch-sensitive control, switch, rotatable control knob or slider. Also,the range and type of visual indicators can vary, e.g. the indicatorscan include LEDs, an LCD or electroluminescent display.

[0027] The control panel of FIG. 3 includes an on/off button 201 to turnthe mains power supply to the machine on/off; a set of control buttons210 and associated indicators 215 for selecting the wash programme(cotton, synthetics, wool, delicates etc.); a control button 230 and anassociated set of indicators for selecting the wash temperature (20-85°C.); a control button 240 and an associated set of indicators forselecting spin speed (0-1600 rpm); a control button 250 and anassociated set of indicators for selecting wash intensity (light,normal, heavy); a set of control buttons 260 and an associated set ofindicators 265 for selecting special features (minimum crease, pre-wash,extra rinse etc.); a plurality of memory buttons 270, 271, 272 forselecting a combination of stored settings; a start button 280 forstarting the machine according to the settings programmed by a user, anda cancel button 282. A further indicator 283 indicates when the door 30of the machine is locked and indicator 284 indicates when the child lockmode is active.

[0028] An LCD display 220 displays text messages at various stagesduring operation of the machine to help a user select programme settingsand to indicate the progress of the machine through the wash cycle.

[0029] There are two basic types of drum mode: a counter-rotating modein which the drum portions 60, 70 are rotated relative to one anotherand a normal mode in which the drum portions 60, 70 are rotated inunison in the same direction in a conventional manner.

[0030] The following table gives details of five drum modes. Each drummode comprises a repeated sequence of four steps. For example, the‘Counter Rotation’ operation performs: a first step whichcounter-rotates the drum portions 60, 70 with respect to one another for13 s; a second step which rests for 6 s with no drum action; a thirdstep which counter-rotates the drum portions 60, 70 with respect to oneanother for 13 s in the opposite direction to that used in action 1; anda fourth step which rests for 6 s with no drum action. Clearly, any ofthe parameters of the drum operations defined here could be varied asappropriate. Drum Mode Step no. Duration (s) Drum speed (rpm) CounterRotation 1 13 52 (CR) 2 6 0 3 13 −52 4 6 0 Counter Rotation 1 10 52Normal 2 32 0 (CRN) 3 10 −52 4 32 0 Normal Action 1 11 52 (NA) 2 5 0 311 −52 4 5 0 Gentle Action 1 6 52 (GA) 2 12 0 3 6 −52 4 12 0 SuperGentle Action 1 6 52 (SGA) 2 27 0 3 6 −52 4 27 0

[0031] FIGS. 4A-4C illustrate steps numbers 1-3 for the counter-rotatingdrum modes. The drum portions 50, 60 firstly rotate in opositedirections (FIG. 4A), then rest (FIG. 4B), then rotate in oppositedirections (FIG. 4C) with each drum portion 60, 70 rotating in adifferent direction to that in FIG. 4A and finally rest (not shown.)FIGS. 5A-5C illustrate actions for the normal drum modes. The drumportions 60, 70 firstly rotate in unison in the same direction (FIG.5A), then rest (FIG. 5B), then rotate in unison (FIG. 5C) in theopposite direction to that in FIG. 5A and finally rest (not shown.)

[0032] In the above table, the Counter Rotations (CR) and CounterRotation Normal (CRN) modes differ in the ratio of time when the drumsare rotating (and therefore agitating the load) and when the drums areat rest. In the CR mode the drums are rotating for roughly twice thetime that they are at rest whereas in the CRN mode the drums are at restfor roughly three times the time that they are rotating. Similarly, withthe normal modes, the modes differ in the ratio of time when the drumsare rotating (and therefore agitating the load) and when the drums areat rest. While the modes detailed above all operate at the same drumspeed of 52 rpm it is possible to vary the drum speed between modes tovary the amount of agitation that these modes provide.

[0033]FIGS. 6 and 7 are tables which give full details of a set of washprogrammes performed by the machine 10 and FIG. 8 is a key for thesetables. A complete wash cycle comprises the following stages: prewash(if the user has selected this), main wash, rinse, final rinse and finalspin. Each of these stages comprises a number of steps. During each stepthe machine operates with a combination of an amount of water, a watertemperature and a drum mode 400 detailed in the tables. As is well-knownwith conventional wash programes, the water temperature that is usedduring the wash programme varies according to the type of fabric beingwashed, with robust fabrics such as cotton being washed at a highertemperature than delicates.

[0034] During the stages of the wash cycle, and particularly during themain wash (see “Main Wash” step no. 3, FIG. 6) the machine operates witha drum mode which is dependent on the wash programme. The most robustfabric types such as cottons, synthetics and dedicates use the CR drummode (long burst of counter-rotation followed by a short rest); wool andcare+ use the CRN drum mode (short burst of counter-rotation followed bya long rest) and the duvet programme does not use counter-rotation atall, since the load comprises one large article which is expected tofill the drum, conditions which are not suited to the use of acounter-rotating drum mode. The length of the wash step (see “Main Wash”step no. 3, FIG. 6) varies according to the amount of soiling of thearticles in the wash load: 4 minutes for light soiling, 6 minutes fornormal soiling and 10 minutes for heavy soiling. A user selects theintensity of the wash via control 250 on the control panel 120. However,as an alternative to varying the length of time for the wash step, thecontroller can vary the amount of agitation by varying the drum mode.Increased agitation can be provided by using a drum mode which rotatesthe drum portions 60, 70 at a higher speed relative to one another orwith a longer ratio of rotation time to rest time.

[0035] Variations to the described embodiments are intended to fallwithin the scope of the present invention. While five drum modes aredescribed here, it is possible to provide more modes which vary in theamount of agitation they apply to the wash load. The modes can vary inthe ratio of rotating time to rest time and/or speed of rotation. Thedrum 50 can comprise more than just the two rotatable portions 60, 70.Three or more separately rotatable portions can be provided, all lyingalongside one another along the axis of rotation.

1. A laundry appliance comprising a drum for receiving articles to belaundered, the drum comprising at least two rotatable drum portions anda drive capable of operating the drum in a plurality of different drummodes, including a drum mode in which the rotatable drum portions aredriven so as to cause relative rotation between the adjacent rotatabledrum portions, and a controller which is capable of controlling theappliance to perform a plurality of different wash programmes, each washprogramme having an associated drum mode.
 2. A laundry applianceaccording to claim 1 wherein each wash programme comprises a sequence ofstages, there being a drum mode associated with each stage.
 3. A laundryappliance according to claim 1 or 2 wherein the drum modes comprise arepeated sequence of steps in which, in one of the steps, the drumportions are rotated relative to one another and in another step thedrum portions are not rotated, at least two of the drum modes differingin the length of time for each of the steps.
 4. A laundry applianceaccording to any one of the preceding claims wherein at least some ofthe drum modes differ in the speed at which the drum is rotated.
 5. Alaundry appliance according to any one of the preceding claims wherein,in at least some of the drum modes, the drum portions are rotated inopposite directions to one another.
 6. A laundry appliance according toany one of the preceding claims wherein, in one of the wash programmes,the controller controls the drive to operate in a drum mode in which thedrum portions are not rotated relative to one another at any pointduring the wash programme.
 7. A laundry appliance according to any oneof the preceding claims wherein the controller also controls the drummode according to the load in the drum.
 8. A laundry appliance accordingto any one of the preceding claims further comprising a control panelfor allowing a user to select a required wash programme, and wherein thecontroller is responsive to a selection made by a user on the controlpanel.
 9. A laundry appliance according to claim 8 wherein the controlpanel also allows a user to select an intensity for the chosen washprogramme, and wherein the controller is arranged to vary, in use, theintensity of the wash programme in accordance with the selection made bya user.
 10. A laundry appliance according to claim 9 wherein thecontroller is arranged to vary the intensity of the wash programme byvarying the length of the wash portion of the wash programme.
 11. Alaundry appliance according to claim 9 wherein the controller isarranged to vary the intensity of the wash programme by varying theratio of time during which the drum portions are rotated relative to oneanother compared to the time during which the drum portions are notrotated.
 12. A laundry appliance according to claim 9 wherein thecontroller is arranged to vary the intensity of the wash programme byvarying the speed of relative rotation between the drum portions.
 13. Acontrol apparatus for a laundry appliance comprising a drum forreceiving articles to be laundered, the drum comprising at least tworotatable drum portions and a drive capable of operating the drum in aplurality of different drum modes, including a drum mode in which therotatable drum portions are driven so as to cause relative rotationbetween the adjacent rotatable drum portions, the control apparatusbeing arranged to control the appliance, in use, to perform a pluralityof different wash programmes, each wash programme having an associateddrum mode.
 14. A laundry appliance or a control apparatus for a laundryappliance substantially as described herein with reference to theaccompanying drawings.